The air defence services business at Tata A&D will be helmed by Sukaran Singh, the CEO of Tata Advanced Systems. The $100-billion-plus conglomerate intends to bring the defence and aerospace business, spread across various listed and unlisted companies, under Tata A&D. The consolidation, after the statutory and regulatory approvals, will make Tata A&D the largest private sector and the third-largest defence player in the country.

On the reasons for his departure, the company said Rajan (49) has "conveyed personal reasons for his decision to leave Tata Sons and has indicated he will be evaluating certain entrepreneurial pursuits in the coming months".